Let’s play with ECLAIRs

The IMASCOD simulator (for CODed MASk Imaging) is a simplified way to illustrate the ECLAIRs coded-aperture telescope imaging process. This simulator was programmed in Python language, originally as a demonstrator for school and CEA open days.

This simulator makes it possible to build the image recorded by the detector. Once the image is created, an algorithm based on the same principle as that applied in the system of gamma-ray bursts trigger (Scientific Processing Unit) on board ECLAIRs is used.


To begin, choose the position of a point source in the sky (a burst gamma for example) that will be detected by ECLAIRs. This position is expressed in cartesian coordinates (x, y) in the field of view of the telescope, where the position x = 0, y = 0 corresponds to the lower left corner. The size of the sky image is 200 × 200 (x and y should not exceed 199).

Once the position is defined, the photons of the source are propagated through the instrument. In the same way, photons of the diffuse background noise of the sky are added.

When you have updated the input parameters, click on « Run »! The results will first display the image of the detector plane recorded by ECLAIRs, then the image of the reconstructed sky.




Number of photons of the source

Number of photons of the background noise